Clicking from sensor?

This doesn't make any sense even to me but I'm out of ideas. Sorry for my first post being a seemingly stupid troubleshooting issue.

There is a clicking coming from my front wheel. My bike is a brand new GF X-Cal with a Trek 9i wireless computer. The click is once per revolution, and appears to be happening when the magnet passes the sensor. It seems to only happen once I have been riding for a while. When I have time to work on it in the garage I can't make the click happen. Has anyone ever seen this or am I nuts? It doesn't go away with dragging the brake, weight change, or tilting the bike. The only thing I can guess is the sensor...

Thanks. I went to the garage again last night with my wife. I didn't think I could hear it if I just pick the bike up and spin the wheel. But if I do that there is a VERY faint click. Almost inaudible.

So is it also normal for the click to get louder as you ride? I never hear the noise at the start of a ride, but 5-10 min in it gets REALLY loud. Sound is similar to a rock caught in the tire. Once it shows up the noise is there until the end of the ride. It's just really annoying and chintzy sounding. Given that I just dropped a pretty good wad of cash for my new bike, it's even more annoying. I'm just wondering if I should try to exchange the computer for another one.

On a side note - my old wired Trek 'Sensor' (model name) didn't seem to do this.

That certainly sounds strange I agree I think there is something wrong here. For all my cateye computers I find the noise level is very faint and does not change in fact I can't hear it at all when I am riding. Assuming that the magnet is not actually hitting the sensor the only other thing I can think of that sounds similar is when I had a spoke nipple come loose inside the rim and it was like a little rock rattling around causing a similar sound to what you describe that became louder as the wheel spun faster. You could take the magnet off the wheel and see if the noise is still there to confirm whether or not the noise is coming from the sensor. If the noise is still there then it is not the sensor but if it goes away I would bring the computer back to the LBS for a replacement.

Great idea! I was actually thinking I needed to confirm it is the sensor and removing the magnet is super easy. I will do that today. I hope that is the problem and not a rotor or hub issue. Thanks again!